JACA 1 & 2 Homebrew Computer

After some research, I am changing my mind and inclined to use the 74HCT273 (*) as registers.

I need the Reset input and the 3 state output.

There will be:

• 4 chips for IR register (32 bits);
• 2 for PC (16 bits);
• 8 for general use registers (8 bits each).

So I'll need 14 of these guys., so far..

(*) Edit: It's not 74HCT273, the right IC is SN74ALS874BN, not very easy to find on stores, but will save many ICs, since it's the only with both Reset and 3-state outputs.

Still lacks the ST A, [addr] instruction, to save the contents of tha A register to the RAM (actually, the register has only 4 bits and each RAM cell is 8-bit, so it uses just the 4 less significant bits, and the other bits are set to 0, kind of odd, I know, but it's just a proof of concept).

I'm procrastinating a lot this last instruction, because I'm deeply buried in TTL research to the 2nd generation CPU, JACA-2...

Let's see what I chose so far:

-2x 74181 for ALU

-for registers: 74HC574

-for RAM: CY62256

What do you think about these choices? Would you use others?